Read this and it will help a ton with the weight issue.
http://www.ty4stroke.com/viewtopic.php?t=34170
You can go to ECP (K&N like) filters with built in velocity stacks.
You can go to an under tunnel exhaust.
You can bump up your timing a few degrees.
You can move your throttle position sensor to achieve the type of perfomance you are looking for with the sled.
If you do these things you'll have a very powerful RX-1 without the hastles.
Good Luck
PS: You'll find most everything you need on the Totallyamaha forum.
